Water based sealer with superior durability

ABSTRACT

A sealer composition includes a first component and a second component. The first component includes water and a hydroxyl functionalized acrylic resin. The second component includes an epoxy silane cross-linker. Characteristically, the first component and second component are mixed at most 40 hours prior to application of the sealer composition to a substrate.

TECHNICAL FIELD

In at least one embodiment, the present invention is related to waterbased coatings from which a sealing coating can be formed.

BACKGROUND

Paints and related coatings are ubiquitous finding numerous applicationsfor both aesthetic and functional applications. In many applications,coatings are applied to improve the aesthetic appeal of a surface byproviding a uniform and pleasing appearance. In other applications,coatings are used has a clear coat on various substrates to provide somedegree of protection. In additional to the visual effects, paintcoatings can also be applied to porous substrates such as concrete andmasonry for sealing purposes.

In this regard, it is known that many coating compositions do not adherewell to metal substrates such as aluminum. Although prior art coatingcompositions work reasonably well with respect to concrete and masonry,these prior art coatings are known to have only modest durability. Inparticular, these coatings degrade in practice when exposed toenvironmental conditions or when they are washed over time.

Accordingly, there is a need for paint compositions that can durablyseal porous substrates and/or adhere to metal substrates such asaluminum.

SUMMARY

In at least one embodiment, the present invention solves one or moreproblems of the prior art by providing a sealer composition for forminga coating on a substrate. The sealer composition includes a firstcomponent and a second component. The first component includes water anda hydroxyl functionalized acrylic resin. The second component includesan epoxy silane cross-linker. Characteristically, the first componentand second component are mixed prior to application of the sealercomposition to a substrate.

In another embodiment, a sealer composition for forming a coating on asubstrate is provided. The sealer composition includes a first componentand a second component. The first component includes water and ahydroxyl functionalized acrylic resin. The second component includes anepoxy silane cross-linker selected from the group consisting of:glycidoxypropyl trimethoxysilane,

and combinations thereof. Characteristically, the first component andsecond component are mixed at most 40 hours prior to application of thesealer composition to a substrate.

In another embodiment, a method of applying the sealer composition setforth above to a substrate is provided. The sealer composition includesa first component and a second component. The first component includeswater and a hydroxyl functionalized acrylic resin. The second componentincludes an epoxy silane cross-linker. Additional details of the firstand second components and their constituents are set forth above. Thesealer composition is applied by mixing the first component and thesecond component to form a coating mixture. The substrate is coated withthe coating mixture to form an uncured coated substrate. The uncuredcoated substrate is allowed to cure to form a sealer coating on thesubstrate.

Advantageously, the sealer composition of the present invention producescoatings exhibits improved scrub and scratch resistance when compared toprior art compositions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 provides a bar chart comparing the scrub resistance of coatingexamples of the present invention compared to several prior artcoatings.

DETAILED DESCRIPTION

Reference will now be made in detail to presently preferredcompositions, embodiments and methods of the present invention, whichconstitute the best modes of practicing the invention presently known tothe inventors. The Figures are not necessarily to scale. However, it isto be understood that the disclosed embodiments are merely exemplary ofthe invention that may be embodied in various and alternative forms.Therefore, specific details disclosed herein are not to be interpretedas limiting, but merely as a representative basis for any aspect of theinvention and/or as a representative basis for teaching one skilled inthe art to variously employ the present invention.

Except in the examples, or where otherwise expressly indicated, allnumerical quantities in this description indicating amounts of materialor conditions of reaction and/or use are to be understood as modified bythe word “about” in describing the broadest scope of the invention.Practice within the numerical limits stated is generally preferred.Also, unless expressly stated to the contrary: percent, “parts of” andratio values are by weight; the term “polymer” includes “oligomer,”“copolymer,” “terpolymer,” and the like; molecular weights provided forany polymers refers to weight average molecular weight unless otherwiseindicated; the description of a group or class of materials as suitableor preferred for a given purpose in connection with the inventionimplies that mixtures of any two or more of the members of the group orclass are equally suitable or preferred; description of constituents inchemical terms refers to the constituents at the time of addition to anycombination specified in the description, and does not necessarilypreclude chemical interactions among the constituents of a mixture oncemixed; the first definition of an acronym or other abbreviation appliesto all subsequent uses herein of the same abbreviation and appliesmutatis mutandis to normal grammatical variations of the initiallydefined abbreviation; and, unless expressly stated to the contrary,measurement of a property is determined by the same technique aspreviously or later referenced for the same property.

It is also to be understood that this invention is not limited to thespecific embodiments and methods described below, as specific componentsand/or conditions may, of course, vary. Furthermore, the terminologyused herein is used only for the purpose of describing particularembodiments of the present invention and is not intended to be limitingin any way.

It must also be noted that, as used in the specification and theappended claims, the singular form “a,” “an,” and “the” comprise pluralreferents unless the context clearly indicates otherwise. For example,reference to a component in the singular is intended to comprise aplurality of components.

Throughout this application, where publications are referenced, thedisclosures of these publications in their entireties are herebyincorporated by reference into this application to more fully describethe state of the art to which this invention pertains.

In an embodiment, a sealer composition for forming a coating on asubstrate is provided. The sealer composition includes a first componentand a second component. The first component includes water and ahydroxyl functionalized acrylic resin. Typically, the pH of the firstcomponent is less than 7. In particular, the pH of the first componentis from 4 to 6. The second component includes an epoxy silanecross-linker. Characteristically, the first component and secondcomponent are mixed prior to application of the sealer composition to asubstrate. In some refinement, the first and second components are mixedat most 40 hours prior to application of the sealer composition to asubstrate. In a refinement, the first and second components are mixedimmediately prior to 40 hours prior to application of the sealercomposition to a substrate. In other refinements, the first and secondcomponents are mixed up to, in increasing order of preference, 40, 30,20, 10, 5, 3, 2, 1, or 0.5 hours prior to application of the sealercomposition to a substrate.

In a variation, the hydroxyl functionalized acrylic resin includes ahydroxyl functional acrylic polymer. In a refinement, the hydroxylfunctionalized acrylic resin is a solution polymer. In anotherrefinement, the hydroxyl functionalized acrylic resin is an emulsionpolymer. Suitable hydroxyl functionalized acrylic resins are formed fromhydroxyl derivatives of the monomers selected from the group consistingof methacrylate, methyl acrylate, ethyl acrylate, 2-chloroethyl vinylether, 2-ethylhexyl acrylate, hydroxyethyl methacrylate, butyl acrylate,butyl methacrylate, trimethylolpropane triacrylate, pentafluorophenylmethacrylate, pentafluorophenyl acrylate,1,1,1,3,3,3-hexafluoroisopropyl acrylate, bis-(2,2,2-trifluoroethyl)itaconate, bis-(1,1,1,3,3,3-hexafluoroisopropyl), 1H,1H,3H-hexafluorobutyl acrylate, 1H,1H,7H-dodecafluoroheptylmethacrylate, 2,2,2-trifluoroethyl acrylate, 2,2,2-trifluoroethylmethacrylate, aliphatic, fluorinated aliphatic, 1H,1H,2H,2H-Heptadecafluorodecyl methacrylate 532.2 acrylic, 1H,1H,2H,2H-heptadecafluorodecyl acrylate, 1H, 1H,5H-octafluoropentylacrylate, 1H, 1H,3H-tetrafluoropropyl methacrylate,hexafluoro-iso-propyl, 1H,1H,3H-hexafluorobutyl methacrylate, 1H,1H,5H-octafluoropentyl methacrylate, and combinations thereof. In afurther refinement, the hydroxyl functionalized acrylic resin is acopolymer of the hydroxyl monomer derivatives and the monomers (nothydroxyl functionalized) set forth above.

As set forth above, the sealer composition includes an epoxy alkoxysilane cross-linker. Examples of suitable epoxy alkoxy silanecross-linker include, but are not limited to: glycidoxypropyltrimethoxysilane,

and combinations thereof.

In another variation, the hydroxyl functionalized acrylic resin ispresent in an amount of 75 to 95 percent of the dry weight of thecombined weight of the first component and the second component, theepoxy silane cross-linker is present in an amount of 5 to 25 percent ofthe dry weight of the combined weight of the first component and thesecond component with the balance being water. In a refinement, thehydroxyl functionalized acrylic resin is present in an amount of 80 to90 percent of the dry weight of the combined weight of the firstcomponent and the second component and the epoxy silane cross-linker ispresent in an amount of 10 to 20 percent of the dry weight of thecombined weight of the first component and the second component with thebalance being water.

In some variations of the sealer composition, the first componentfurther includes one or more additives selected from the groupconsisting of rheology modifiers, surfactants, defoamers, organicsolvents, pH adjusters, UV stablizers, dispersants, coalescents,biocides, inorganic pigment, organic pigments, and combinations thereof.Therefore, in a refinement, the hydroxyl functionalized acrylic resin ispresent in an amount of 75 to 95 percent of the dry weight of thecombined weight of the first component and the second component, theepoxy silane cross-linker is present in an amount of 5 to 25 percent ofthe dry weight of the combined weight of the first component and thesecond component, and the additives being present in an amount of 0.1 to10 percent of the combined weight of the total formulation with thebalance being water. In one refinement, volatile organic compounds arepresent in an amount less than 100 g/liter.

In a variation, the sealer composition can include a matting agent toadjust the gloss to a lower sheen. The matting agent can be any extenderpigment that does not add opacity to the clear coat, such as silicas,nepheline syenite, and the like. In a refinement, the matting agent ispresent in an amount from about 0.2 to 8 percent of the dry weight ofthe combined weight of the first component and the second component.

In another embodiment, a method of applying the sealer compositions setforth above to a substrate is provided. The sealer composition includesa first component and a second component. The first component includeswater and a hydroxyl functionalized acrylic resin. The second componentincludes an epoxy silane cross-linker. Additional details of the firstand second components and their constituents are set forth above. Thesealer composition is applied by mixing the first component and thesecond component to form a coating mixture. The substrate is coated withthe coating mixture to form an uncured coated substrate. The uncuredcoated substrate is allowed to cure to form a sealer coating on thesubstrate. In one refinement, the substrate is a concrete or masonrysubstrate. In some refinements, the substrate is a pre-coated substratewith paint, coatings or stains, the sealer coating being a cleartopcoat. In another refinement, the substrate is metal. In still anotherrefinement, the substrate is pavement, artificial stone and stucco. Inother refinement, the sealer coating is topcoat over a paint or stain.In still other refinements, the sealer coating is a dry erase coating.

The following examples illustrate the various embodiments of the presentinvention. Those skilled in the art will recognize many variations thatare within the spirit of the present invention and scope of the claims.

Table 1 provides compositions for four examples of embodiments of theinvention. It should be appreciated that the resin and silane choicesare not limited to the listed examples. The gloss was measured on 3 mildrawdown on Leneta 3B card with BYK-Gardner gloss meter.

TABLE 1 Water based high gloss clear concrete sealer formula Example 1Example 2 Example 3 Example 4 Component (gram) (gram) (gram) (gram) PartA water 16.9 20.9 20.7 16.9 solvent 1.1 1.1 1.1 1.1 Hydroxyl acrylicsolution 76.2 76.2 polymer Hydroxyl acrylic latex 73.7 73.9 polymerWetting agent 0.5 0.5 0.5 0.5 Defoamer 0.5 0.5 Defoamer 0.3 0.3 UVstabilizer 0.3 0.3 0.3 0.3 Part B silane A 4.6 3.2 silane B 3.2 silane C4.6 Total 100.0 100.0 100.0 100.0 Properties Gloss at 60 degree 88 86 8281

A matting agent is added into the high gloss formula to adjust the glossto a lower sheen as shown in the compositions of Table 2. The mattingagent can be any extender pigment that does not add opacity to the clearcoat, such as silicas, nepheline syenite etc.

TABLE 2 Water based clear concrete sealer formula Example 5 Example 6Example 7 Component (gram) (gram) (gram) Part A water 21.75 14.15 33.3solvent 1 1 1.1 Hydroxyl acrylic solution polymer 71 79 Hydroxyl acryliclatex polymer 61.4 Wetting agent 1 0.6 0.5 Defoamer 0.5 0.5 0.34 UVstabilizer Matting Pigment 0.75 0.75 0.75 Part B silane A 4 4 2.7 Total100 100 100 Properties Gloss at 60 degree 35 20 12Metal Adhesion

The clear coat adheres to aluminum substrates while similar prior artcompositions do not have this property (see Table 3). Adhesion onaluminum Q-panel (normally considered as a difficult-to-adheresubstrate) indicates this clear coat can be potentially used as a DTMclear coat.

TABLE 3 Crosshatch adhesion on Aluminum Q-Panels crosshatch adhesionSample name dry/wet Invention example formula 1 5B/5B Invention exampleformula 3 5B/5B Prior art SB sample 1 5B/5B Prior art WB sample 2 0B/0BPrior art WB sample 3 0B/0B Prior art WB sample 4 0B/0B Prior art WBsample 5 5B/5B Prior art WB sample 6 0B/0B Prior art WB sample 7 0B/0BDry Erase

The clear coat can be used on top of coated or uncoated surfaces, andexhibits excellent dry erase properties, while the other products in thesealer category do not have this property. This indicates the clear coatcan be used as a dry erase coating.

Experiment: Brush 2 coats of sealer prototypes or commercial sealerproducts on the clay tile, let it dry completely. Draw lines on thecoated tile with Expo Dry Erase Markers, let it dry for 10 min and 24hours, then erase with dry paper towel. The rating is tabulated asbelow, where Y=erasable, N=not erasable.

TABLE 4 Dry erase properties of clear coat Expo Dry Erase Expo Dry EraseMarker (red) Marker (green) Sample name 10 min 24 hr 10 min 24 hrInvention example formula 1 Y Y Y Y Invention example formula 2 Y Y Y YInvention example formula 3 Y Y Y Y Prior art SB sample 1 Y Y Y N Priorart WB sample 2 N N N N Prior art WB sample 3 N N N N Prior art WBsample 4 N N N N Prior art WB sample 5 N N N N Prior art WB sample 6 N NN N Prior art WB sample 7 N N N N

FIG. 1 provides a bar chart comparing the scrub resistance of coatingexamples of the present invention compared to several prior artcoatings. The scrub resistance is determined according to ASTM D2486;the entire disclosure of which is incorporated by reference. The resultsare reported as a percent with respect to a reference sample. Thepercent is the number of cycles to failure for the sample being measureddivided by the number of cycles to failure for a reference sample time100 percent. Typically, the coatings of the invention have a scrubresistance of 900 percent or greater.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms of the invention. Rather,the words used in the specification are words of description rather thanlimitation, and it is understood that various changes may be madewithout departing from the spirit and scope of the invention.Additionally, the features of various implementing embodiments may becombined to form further embodiments of the invention.

What is claimed is:
 1. A sealer composition comprising: a firstcomponent including: water; and a hydroxyl functionalized acrylic resin,wherein the pH of the first component is from 4 to 6; and a secondcomponent consisting of: an epoxy silane cross-linker that includes acombination of

wherein the first component and the second component are mixed at most40 hours prior to application of the sealer composition to a substrate.2. The sealer composition of claim 1 wherein the hydroxyl functionalizedacrylic resin includes a hydroxyl functional—acrylic polymer.
 3. Thesealer composition of claim 1 wherein the hydroxyl functionalizedacrylic resin is a solution polymer.
 4. The sealer composition of claim1 wherein the hydroxyl functionalized acrylic resin is an emulsionpolymer.
 5. The sealer composition of claim 1 wherein: the hydroxylfunctionalized acrylic resin is present in an amount of 75 to 95 percentof the dry weight of a combined weight of the first component and thesecond component; the epoxy silane cross-linker is present in an amountof 5 to 25 percent of the dry weight of a combined weight of the firstcomponent and the second component; and the balance being water.
 6. Thesealer composition of claim 1 wherein: the hydroxyl functionalizedacrylic resin is present in an amount of 80 to 90 percent of the dryweight of a combined weight of the first component and the secondcomponent; the epoxy silane cross-linker is present in an amount of 10to 20 percent of the dry weight of a combined weight of the firstcomponent and the second component; and the balance being water.
 7. Thesealer composition of claim 1 wherein the first component furthercomprises one or more additives selected from the group consisting ofrheology modifiers, surfactants, defoamers, organic solvents, pHadjusters, UV stablizers, dispersants, coalescents, biocides, inorganicpigment, organic pigments, and combinations thereof.
 8. The sealercomposition of claim 7 wherein: the hydroxyl functionalized acrylicresin is present in an amount of 75 to 95 percent of the dry weight ofthe combined weight of the first component and the second component; theepoxy silane cross-linker is present in an amount of 5 to 25 percent ofthe dry weight of a combined weight of the first component and thesecond component; the additives being present in an amount of 0.1 to 10percent of a combined weight of the sealer composition; and the balancebeing water.
 9. The sealer composition of claim 1 wherein volatileorganic compounds are present in an amount less than 100 g/liter.
 10. Asealer composition comprising: a first component including: water; and ahydroxyl functionalized acrylic resin, wherein the pH of the firstcomponent is from 4 to 6; and a second component consisting of: an epoxysilane cross-linker that is

wherein the first component and the second component are mixed at most40 hours prior to application of the sealer composition to a substrate.11. The sealer composition of claim 10 wherein the hydroxylfunctionalized acrylic resin includes a hydroxyl functional acrylicsolution polymer.
 12. The sealer composition of claim 10 wherein thehydroxyl functionalized acrylic resin is a solution polymer or anemulsion polymer.
 13. The sealer composition of claim 10 wherein: thehydroxyl functionalized acrylic resin is present in an amount of 75 to95 percent of the dry weight of a combined weight of the first componentand the second component; the epoxy silane cross-linker is present in anamount of 5 to 25 percent of the dry weight of a combined weight of thefirst component and the second component; and the balance being water.14. The sealer composition of claim 10 wherein the first componentfurther comprises an additive selected form the group consisting ofrheology modifiers, surfactants, defoamers, organic solvents, pHadjusters, UV stablizers, dispersants, coalescents, inorganic pigment,organic pigment, and biocides.
 15. A sealer composition comprising: afirst component consisting of: water; and a hydroxyl functionalizedacrylic resin, wherein the pH of the first component is from 4 to 6; anda second component comprising: an epoxy silane cross-linker including

wherein the first component and the second component are mixed at most40 hours prior to application of the sealer composition to a substrate.16. The sealer composition of claim 15 wherein the hydroxylfunctionalized acrylic resin includes a hydroxyl functional—acrylicpolymer.
 17. The sealer composition of claim 15 wherein the hydroxylfunctionalized acrylic resin is a solution polymer.
 18. The sealercomposition of claim 15 wherein the epoxy silane cross-linker furthercomprises: glycidoxypropyl trimethoxysilane,

and combinations thereof.
 19. The sealer composition of claim 15wherein: the hydroxyl functionalized acrylic resin is present in anamount of 75 to 95 percent of the dry weight of a combined weight of thefirst component and the second component; the epoxy silane cross-linkeris present in an amount of 5 to 25 percent of the dry weight of acombined weight of the first component and the second component; and thebalance being water.
 20. The sealer composition of claim 15 wherein: thehydroxyl functionalized acrylic resin is present in an amount of 80 to90 percent of the dry weight of a combined weight of the first componentand the second component; the epoxy silane cross-linker is present in anamount of 10 to 20 percent of the dry weight of a combined weight of thefirst component and the second component; and the balance being water.21. The sealer composition of claim 15 wherein volatile organiccompounds are present in an amount less than 100 g/liter.
 22. The sealercomposition of claim 15 wherein the first component further comprisesone or more additives selected from the group consisting of rheologymodifiers, surfactants, defoamers, organic solvents, pH adjusters, UVstablizers, dispersants, coalescents, biocides, inorganic pigment,organic pigments, and combinations thereof.
 23. The sealer compositionof claim 22 wherein: the hydroxyl functionalized acrylic resin ispresent in an amount of 75 to 95 percent of the dry weight of thecombined weight of the first component and the second component; theepoxy silane cross-linker is present in an amount of 5 to 25 percent ofthe dry weight of a combined weight of the first component and thesecond component; the additives being present in an amount of 0.1 to 10percent of a combined weight of the sealer composition; and the balancebeing water.
 24. The sealer composition of claim 15 wherein the epoxysilane cross-linker further comprises: